U.S. patent application number 13/563467 was filed with the patent office on 2014-02-06 for noninvasive measuring device and noninvasive measuring method for probing an interface.
This patent application is currently assigned to NATIONAL TAIWAN UNIVERSITY. The applicant listed for this patent is Chien-Cheng Chen, Chi-Kuang Sun, Yu-Chieh Wen. Invention is credited to Chien-Cheng Chen, Chi-Kuang Sun, Yu-Chieh Wen.
Application Number | 20140033821 13/563467 |
Document ID | / |
Family ID | 50024163 |
Filed Date | 2014-02-06 |
United States Patent
Application |
20140033821 |
Kind Code |
A1 |
Sun; Chi-Kuang ; et
al. |
February 6, 2014 |
NONINVASIVE MEASURING DEVICE AND NONINVASIVE MEASURING METHOD FOR
PROBING AN INTERFACE
Abstract
The present disclosure provides solutions to probing an
interface. With a noninvasive measuring device provided in one
embodiment of the disclosure, an acoustic wave whose frequency is
higher than approximately 300 GHz is generated to propagate in a
buffering film. With measuring the reflection from the interface of
an object to be measured interfacing with the buffering film, it is
possible in one embodiment of the disclosure that at least one
physical property of the interface may be analyzed, preferably with
approximately 0.3 nm resolution.
Inventors: |
Sun; Chi-Kuang; (Taipei,
TW) ; Chen; Chien-Cheng; (Taipei, TW) ; Wen;
Yu-Chieh; (Taipei, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sun; Chi-Kuang
Chen; Chien-Cheng
Wen; Yu-Chieh |
Taipei
Taipei
Taipei |
|
TW
TW
TW |
|
|
Assignee: |
NATIONAL TAIWAN UNIVERSITY
Taipei
TW
|
Family ID: |
50024163 |
Appl. No.: |
13/563467 |
Filed: |
July 31, 2012 |
Current U.S.
Class: |
73/627 ; 977/755;
977/954 |
Current CPC
Class: |
G01N 29/2418 20130101;
G01N 29/4436 20130101; G01N 2291/015 20130101; G01N 29/348
20130101; G01N 2291/022 20130101; G01N 29/30 20130101; G01N
2291/02827 20130101; G01N 2291/0237 20130101; G01N 29/46 20130101;
G01N 2291/02818 20130101; B82Y 15/00 20130101; G01N 2291/023
20130101; G01N 2291/042 20130101 |
Class at
Publication: |
73/627 ; 977/755;
977/954 |
International
Class: |
G01N 29/24 20060101
G01N029/24 |
Claims
1. A noninvasive measuring device for probing an interface, the
device comprising: a transducer operable to generate and detect an
acoustic wave with a frequency higher than about 300 GHz; a
buffering film covering the transducer and operable to have an
interface with an object to be measured; wherein the acoustic wave
is operable to interact with the object to be measured and the
buffering film; and a photo measuring unit operable to measure a
reflection of the acoustic wave to analyze at least one physical
property of the interface.
2. The noninvasive measuring device according to claim 1, further
comprising: at least one optical unit operable to generate a
plurality of optical pumping pulses and a plurality of optical
probing pulses; wherein the transducer is operable to receive the
optical pumping pulses in order to generate the acoustic wave and
the optical probing pulses, wherein the optical probing pulses are
an inverse wave of the optical pumping pulses and are operable to
be delayed for a controllable time in order to generate an inverse
acoustic wave.
3. The noninvasive measuring device according to claim 2, wherein
the optical pumping pulses and the optical probing pulses are
coherent optical pulses.
4. The noninvasive measuring device according to claim 1, wherein
the transducer further comprises: at least one quantum well formed
by a semiconductor material or thin metal film.
5. The noninvasive measuring device according to claim 4, wherein
the quantum well forms a lattice mismatch between the buffering
film and the semiconductor material where stress is induced to
generate a plurality of acoustic phonons.
6. The noninvasive measuring device according to claim 4, wherein
the semiconductor material is chosen from the group of InGaN and
InGaAs.
7. The noninvasive measuring device according to claim 1, wherein
the buffering film is chosen from the group of GaN and GaAs.
8. The noninvasive measuring device according to claim 1, wherein a
thickness of the semiconductor material is about 3 nm and a
thickness of the buffering film is within the range from about 7 nm
to 80 nm.
9. The noninvasive measuring device according to claim 1, wherein
the object to be measured is in any one state of fluid, solid, and
gas.
10. The noninvasive measuring device according to claim 9, wherein
the object to be measured comprises any one of water, ice,
sapphire, silicon, and silicon oxide.
11. The noninvasive measuring device according to claim 1, wherein
the photo measuring unit is operable to measure a change of
transmission or a change of reflectivity of a reflection of the
acoustic wave in order to analyze the at least one physical
property of the interface.
12. The noninvasive measuring device according to claim 11, wherein
the at least one analyzed physical property comprises at least one
of: acoustic attenuation, surface roughness, spectrum loss, mass
density, elastic modulus, and bulk viscosity.
13. The noninvasive measuring device according to claim 1, wherein
the reflection of the acoustic wave is measured with about 0.3 nm
resolution within 30 ps.
14. The noninvasive measuring device according to claim 1, wherein
the frequency of the acoustic wave is within the range from about
300 GHz to 1.4 THz.
15. A noninvasive measuring method for probing an interface, the
method comprising: providing a transducer whose thickness is
between about 1 nm to 10 nm and is covered by a buffering film
operable to generate an acoustic wave whose frequency is higher
than about 300 GHz; calibrating with a measurement of a reflection
of the acoustic wave reflecting at a surface of the buffering film
that is not affected by an object to be measured; measuring a
reflection of the acoustic wave reflecting at an interface between
the buffering film and the object to be measured; and comparing the
two measured reflections to analyze at least one physical property
of the interface.
16. The noninvasive measuring method according to claim 15, further
comprising: generating a plurality of optical pumping pulses; and
generating a plurality of optical probing pulses; wherein the
transducer is operable to receive the optical pumping pulses in
order to generate the acoustic wave and the optical probing pulses,
wherein the optical probing pulses are an inverse wave of the
optical pumping pulses and are operable to be delayed for a
controllable time in order to generate an inverse acoustic
wave.
17. The noninvasive measuring method according to claim 15, wherein
providing the transducer further comprises: forming at least one
quantum well by a semiconductor material that is operable to form a
lattice mismatch between the buffering film and the semiconductor
material where stress is operable to induce and generate a
plurality of acoustic phonons.
18. The noninvasive measuring method according to claim 15, wherein
the measurement of the reflection of the acoustic wave that is not
affected by the object to be measured is a measurement of the
reflection of the acoustic wave reflecting from a surface of the
buffering film interfacing with air.
19. The noninvasive measuring method according to claim 15, wherein
the object to be measured comprises any one of water, ice,
sapphire, silicon, and silicon oxide.
20. The noninvasive measuring method according to claim 15, wherein
the measurements of the reflection of the acoustic wave is of the
change of transmission or the change of reflectivity of the
reflection of the acoustic wave.
21. The noninvasive measuring method according to claim 15, wherein
the analyzed physical property comprises any one of: acoustic
attenuation, surface roughness, spectrum loss, mass density,
elastic modulus, and bulk viscosity.
22. The noninvasive measuring method according to claim 15, wherein
the frequency of the acoustic wave is within the range from about
300 GHz to 1.4 THz.
23. A noninvasive measuring method for probing an interface, the
method comprising: providing a transducer whose thickness is
between about 1 nm to 10 nm and is covered by a buffering film
operable to generate an acoustic wave whose frequency is higher
than about 300 GHz; calibrating with a measurement of a reflection
of the acoustic wave reflecting at an interface between the
buffering film and an object to be measured; measuring a reflection
of the acoustic wave reflecting at a surface of the object to be
measured free from the interface between the buffering film and the
object to be measured; and comparing the two measured reflections
to analyze at least one physical property of the interface.
24. The noninvasive measuring method according to claim 23, further
comprising: generating a plurality of optical pumping pulses; and
generating a plurality of optical probing pulses; wherein the
transducer is operable to receive the optical pumping pulses in
order to generate the acoustic wave and the optical probing pulses,
wherein the optical probing pulses are an inverse wave of the
optical pumping pulses and are operable to be delayed for a
controllable time in order to generate an inverse acoustic
wave.
25. The noninvasive measuring method according to claim 23, wherein
providing the transducer further comprises: forming at least one
quantum well by a semiconductor material that is operable to form a
lattice mismatch between the buffering film and the semiconductor
material where stress is operable to induce and generate a
plurality of acoustic phonons.
26. The noninvasive measuring method according to claim 23, wherein
the object to be measured comprises any one of water, ice,
sapphire, silicon, and silicon oxide.
27. The noninvasive measuring method according to claim 23, wherein
the measurement of the reflection of the acoustic wave is one of
the change of transmission or the change of reflectivity of the
reflection of the acoustic wave.
28. The noninvasive measuring method according to claim 23, wherein
the analyzed physical property comprises one of: acoustic
attenuation, surface roughness, spectrum loss, mass density,
elastic modulus, and bulk viscosity.
29. The noninvasive measuring method according to claim 23, wherein
the frequency of the acoustic wave is within the range from about
300 GHz to 1.4 THz.
Description
FIELD OF THE INVENTION
[0001] The present disclosure generally relates to a noninvasive
measuring device and noninvasive measuring method for probing an
interface, and more particularly, to a noninvasive measuring device
and noninvasive measuring method for probing an interface through
an acoustic wave.
BACKGROUND
[0002] Interfaces between two different materials or mixtures play
important rolls in many situations for their physical properties.
For example, the wetting of an interface between a solid and a
fluid is important for controlling the progress of a chemical
reaction. The physical and chemical properties of interfacial water
existing within 45 .ANG. from the interface, are quite different
from that of bulk water existing in the rest part that affect not
only the wetting of surfaces, but also reactions of water
purification, protein folding, hydrogen energy, and so on.
[0003] Currently, some approaches have been developed for probing
interfacial water, such as atomic force microscopy, surface force
apparatus, sum-frequency vibration spectroscopy, X-ray diffraction
spectroscopy, ultrafast electron crystallography, low energy
electron diffraction, scanning tunneling microscopy, neutron
diffraction, nuclear magnetic resonance, and so on. Only the first
two approaches listed above can probe the intermolecular
interaction between interfacial water with a substrate, but both
techniques are invasive. In addition, they are quasi-static
measurements, inevitably facing the inability to picosecond-scale
structural relaxation dynamics.
[0004] Therefore, there is still a need for developing a
noninvasive technique for probing an interface in a shorter
measuring time.
BRIEF SUMMARY OF THE DISCLOSURE
[0005] An object of the present disclosure is to provide a
noninvasive measuring device and noninvasive measuring method for
probing an interface that measures the interface to analyze at
least one physical property through acoustic waves. According to
one embodiment of the disclosure, the noninvasive measuring device
and noninvasive measuring method for probing an interface are
versatile for an object of any state, including fluid, solid, and
gas to obtain the analyzed physical property including, roughness,
spectrum loss, mass density, elastic modulus, and bulk viscosity.
According to another embodiment of the disclosure, the noninvasive
measuring device and noninvasive measuring method for probing an
interface could even measure the reflection of the acoustic wave
with approximately 0.3 nm resolution.
[0006] In one aspect of the disclosure, an embodiment of the
disclosure comprises a noninvasive measuring device for probing an
interface, the device comprising a transducer, a buffering film, an
object to be measured, and a photo measuring unit. The transducer
generates and detects an acoustic wave with a frequency that is
higher than approximately 300 GHz; the buffering film covers the
transducer; the object to be measured interfaces with the buffering
film through the interface, where the acoustic wave interacts with
the object to be measured and the buffering film; and the photo
measuring unit measures the reflection of the acoustic wave to
analyze at least one physical property of the interface.
[0007] In another aspect of the disclosure, an embodiment of the
disclosure comprises a noninvasive measuring method for probing an
interface, the method comprising the steps of: providing a
transducer whose thickness is between approximately 1 nm to 10 nm
and is covered by a buffering film to generate an acoustic wave
with a frequency that is higher than approximately 300 GHz;
calibrating with the measurement of the reflection of the acoustic
wave reflecting at the surface of the buffering film that is not
affected by an object to be measured; measuring the reflection of
the acoustic wave reflecting at the interface between the buffering
film and the object to be measured; and comparing the two measured
reflections to analyze at least one physical property of the
interface.
[0008] In yet another aspect of the disclosure, an embodiment of
the disclosure comprises a noninvasive measuring method for probing
an interface, the method comprising the steps of: providing a
transducer whose thickness is between approximately 1 nm to 10 nm
and is covered by a buffering film to generate an acoustic wave
with a frequency that is higher than approximately 300 GHz;
calibrating with the measurement of the reflection of the acoustic
wave reflecting at the interface between the buffering film and an
object to be measured; measuring the reflection of the acoustic
wave reflecting at the surface of the object to be measured free
from the interface between the buffering film and the object; and
comparing the two measured reflections to analyze at least one
physical property of the interface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various objects to be measured and advantages of the present
disclosure will be more readily understood from the following
detailed description when read in conjunction with the appended
drawings, in which:
[0010] FIG. 1 depicts a schematic diagram of a noninvasive
measuring device for probing an interface according to an
embodiment of the present disclosure;
[0011] FIGS. 2(a), 2(b), 2(c), and 2(d) depict several exemplary
types of the sample used in an embodiment of the present
disclosure;
[0012] FIGS. 3(a), 3(b), 3(c), and 3(d) depict the measurements of
the reflection of the acoustic wave obtained from the samples shown
in FIG. 2(a), FIG. 2(b), FIG. 2(c), or FIG. 2(d) according to an
embodiment of the present disclosure;
[0013] FIG. 4 depicts an exemplary sample used for measuring an
interface with ice according to an embodiment of the present
disclosure;
[0014] FIG. 5(a) depicts the temporal trace of the measured results
of the interface between the buffering film and the object to be
measured and between the buffering film and vacuum before the
object to be measured is installed or positioned on the buffering
film according to an embodiment of the present disclosure;
[0015] FIG. 5(b) depicts the Fourier spectra of the interface
before and after installing the object to be measured according to
an embodiment of the present disclosure;
[0016] FIG. 6(a) depicts an exemplary sample used in the present
embodiment;
[0017] FIG. 6(b) depicts another exemplary sample used in the
present embodiment;
[0018] FIGS. 7(a) to 7(b) depict a comparison chart of the
reflectivity or phase of the measured reflection of the acoustic
wave versus two different theory curves, wherein one is the theory
curve of interfacial water (marked by B) and the other is the
theory curve of bulk water (marked by C) according to an embodiment
of the present disclosure;
[0019] FIGS. 8(a) to 8(c) depict exemplary charts of several
analyzed physical property of the interface;
[0020] FIG. 9 depict a flowchart for an embodiment of a noninvasive
measuring method for probing an interface according to the
disclosure; and
[0021] FIG. 10 depicts a flowchart for another embodiment of a
noninvasive measuring method for probing an interface according to
the disclosure.
DETAILED DESCRIPTION
[0022] Referring now to FIGS. 1 and 2(a), wherein FIG. 1 depicts a
schematic diagram of a noninvasive measuring device 1 for probing
an interface according to an embodiment of the present disclosure,
and wherein FIG. 2(a) depicts a perspective view of a type of the
sample used in the present embodiment. As shown, the noninvasive
measuring device 1 comprises an optical unit 11, a sample 12, and a
photo measuring unit 13. The optical unit 11 comprises an exemplary
femtosecond laser source 111 that generates a plurality of coherent
optical pumping pulses marked by bold lines and a plurality of
coherent optical probing pulses marked by thin lines which is an
inverse wave of the optical pumping pulses but delayed for a
controllable time through a PBS (Polarizing Beam Splitter) cube.
For adjusting the optical characteristics of the laser pulses, many
optical devices are used herein, such as doubling the frequency by
a BBO (Betabarium-borate) crystal, controlling the beam path by one
or more minors, and controlling the focus by an objective lens, and
so on. In other embodiments of the present disclosure, other
structures or types of optical units may be used, and some of the
elements inside the optical unit may be added or omitted. The photo
measuring unit 13 comprises a photo detector 131 and an analyzing
element 132. Outside of the sample 12, the thinner arrow directing
to the sample 12 represents the optical probing pulses, the thicker
arrow directing to the sample 12 represents the optical pumping
pulses, and the arrow opposite to the sample 12 represents the
reflection of the optical probing pulses and the optical pumping
pulses.
[0023] As shown in FIG. 2(a), the sample 12 comprises a GaN film
120, a transducer 121, a buffering film 122 covering the transducer
121, and an object to be measured 123 interfacing with the
buffering film through an interface 124. The formation of the
sample 12 is exemplarily accomplished by sequentially forming the
GaN film 120, the transducer 121, the buffering film 122, the
object to be measured 123 one-by-one through means of vapor
deposition, sputtering, adhesive materials, mounting devices, etc.
The material of the transducer 121 used to form at least one
quantum well could be a semiconductor material or thin metal film,
such as that chosen from the group of InGaN and InGaAs, and in the
present embodiment, the transducer 121 is made of 3 nm thick InGaN
forming a single quantum well 1211. The buffering film could be
chosen from the group of GaN and GaAs, and in the present
embodiment, the buffering film 122 is made of 7 nm thick n-type
GaN. The object to be measured 123 is not limited to any state of
fluid, solid, and/or gas or any type of material, but for example,
the object to be measured 123 could be any one of water, ice,
sapphire, silicon and silicon oxide, and in the present embodiment
is a sapphire substrate. When the optical pumping pulses and the
optical probing pulses incident onto the free surface of the sample
12, i.e. the left surface shown in the figure, the transducer 121
receives the optical pumping pulses and the optical probing pulses,
and the quantum well 1211 of the transducer 121 forms a lattice
mismatch between the material of the transducer 121 and the
buffering film 122 where stress is induced to generate a plurality
of acoustic phonons. The acoustic phonons form an acoustic wave
whose frequency is higher than 300 GHz (marked by the hollow
arrows) and an inverse acoustic wave which is not shown inside the
sample 12 in the figure. Here, in the present embodiment,
preferably, the frequency of the acoustic wave is about 1 THz, such
as 890 GHz used here, or over 1 THz, for example, 1.4 THz. These
acoustic wave and inverse acoustic wave generate inverse
piezoelectric coupling inside the sample 12 to affect the optical
transmission of the interface between the buffering film 122 and
the object to be measured 123. Through the inverse piezoelectric
effect, the acoustic wave could be detected.
[0024] Referring now to FIG. 3(a), the measurement of the
reflection of the acoustic wave obtained from the sample 12 is
depicted in FIG. 2(a). With the ultrasound frequency of the
acoustic wave, the photo measuring unit 13 comprising the photo
detector 131 and the analyzing element 132 could measure the
reflection of the acoustic wave (marked by the solid arrow pointed
to the left in FIG. 2(a)), such as the change of transmission, the
change of reflectivity of the reflection of the acoustic wave or
other optical property, reflecting from the interface 124 where the
acoustic wave interacts with the object to be measured 123 and the
buffering film 122 to analyze at least one physical property of the
interface 124 with 0.3 nm resolution within 30 ps. The analyzed
physical property comprises: acoustic attenuation, surface
roughness, spectrum loss, mass density, elastic modulus, and bulk
viscosity. Here, from the specular scattering probability of
acoustic phonons at crystal boundary, which may be induced by a
roughness of the interface 124, the nanoscaled irregularity and
roughness of the interface 124 could be noninvasively analyzed.
Additionally, for a more conscientious result, before forming the
object to be measured 123, it may be preferable to carry on
calibration first, for example calibration with the measurement of
the reflection of the acoustic wave, which is not affected by an
object to be measured 123, reflecting from the right surface of the
buffering film 122 where is predetermined to form the object to be
measured 123. Then, this measurement for calibration can be
compared with the measurement of the reflection of the acoustic
wave after forming the buffering film 122.
[0025] Referring now to FIGS. 2(b), 2(c), and 2(d) and FIGS. 3(b),
3(c), and 3(d), wherein FIGS. 2(b), 2(c), and 2(d) depict other
types of samples 12 that may be used in the present embodiment, and
FIGS. 3(b), 3(c), and 3(d) show the measurements of the reflection
of the acoustic wave obtained from the sample 12 shown in FIG.
2(b), FIG. 2(c), or FIG. 2(d) accordingly. For a clear comparison,
the differences between these types of the sample 12 and what is
shown in FIG. 2(a) include: in the sample 12 shown in FIG. 2(b),
the object to be measured 125 is a silicon substrate attached on
the opposite surface of the buffering film 122, which is made of
GaN, and the acoustic wave reflects at the free surface 126 which
is the interface between the silicon substrate and air; in the
sample 12 shown in FIG. 2(c), the object to be measured 123 is
still a sapphire substrate, but the transducer 121 is made of
several layers of semiconductor material, such as InGaN, forming a
multi-quantum well 1212; and in the sample shown in FIG. 2(d), the
object to be measured 123 is a silicon oxide film 127.
[0026] Referring now to FIGS. 4, 5(a), and 5(b) for another
embodiment of the present disclosure, wherein FIG. 4 depicts a
sample used for measuring an interface with ice 128, FIG. 5(a)
depicts the temporal trace of the measured results, i.e. the change
of the transmittance, of the interface 124 between the buffering
film 122 and the object to be measured 128, i.e. ice, and between
the buffering film 122 and vacuum before the object to be measured
128 is installed or positioned on the buffering film 122, and FIG.
5(b) depicts the Fourier spectra of the interface 124 before and
after installing the object to be measured 128. It is to be note
that the transducer 1211 forms a single quantum well in the present
embodiment; however, multi-quantum well or other types of
transducer to generate phonons may also be applicable. As shown in
FIG. 5(b), the acoustic reflection spectra is a complex which could
be derived based on the formula as follows:
R ( .omega. ) = Z GaN ( .omega. ) - Z Ice ( .omega. ) Z GaN (
.omega. ) + Z Ice ( .omega. ) ##EQU00001##
[0027] wherein Z designates a complex acoustic impedance, and it
relates to .rho. (mass density) through Z=.rho.V.sub.complex,
wherein V.sub.complex designates acoustic velocity, which could be
derived based on the formula as follows:
V complex ( .omega. ) = .omega. k ( .omega. ) - .alpha. ( .omega. )
##EQU00002##
[0028] Additionally, according to Stoke's Law:
.rho. .differential. 2 u .differential. t 2 = A .differential. 2 u
.differential. x 2 + b .differential. 2 .differential. x 2
.differential. u .differential. t ##EQU00003##
[0029] wherein A represents elastic modulus and b represents bulk
viscosity, with the dispersion relation and loss spectrum relation
listed bellow:
k 2 = .omega. 2 .rho. 2 A [ 1 1 + .omega. 2 .tau. 2 + 1 1 + .omega.
2 .tau. 2 ] ##EQU00004## .alpha. 2 = .omega. 2 .rho. 2 A [ 1 1 +
.omega. 2 .tau. 2 - 1 1 + .omega. 2 .tau. 2 ] ##EQU00004.2##
[0030] the curves of mass density, elastic modulus, and bulk
viscosity can be analyzed.
[0031] Referring now to FIGS. 6(a), 6(b), 7(a), 7(b), 8(a), 8(b),
and 8(c) for yet another embodiment of the present disclosure,
wherein FIG. 6(a) depicts a sample used in the present embodiment,
FIG. 6(b) depicts a sample used in the present embodiment, FIGS.
7(a) and 7(b) depict a comparison chart of the reflectivity or
phase of the measured reflection of the acoustic wave (marked by A)
versus two different theory curves, one is the theory curve of
interfacial water (marked by B) and the other is the theory curve
of bulk water (marked by C), and FIGS. 8(a) to 8(c) depict
exemplary charts of several analyzed physical property of the
interface 124, i.e. the interfacial water around the interface 124.
As shown in FIG. 6(a), the object to be measured 129, i.e. water or
fluid, interfaces with the buffering film 122, which may be 80 nm
thick GaN, by interface 124 in the present embodiment. For
controlling the water or fluid, a tank 130 with an inlet and an
outlet, as shown in FIG. 6(b), can be used. When measuring the
reflection of the acoustic wave whose frequency could be in the
range of 300 GHz to 1.4 THz, the water or fluid could flow in the
tank 130. Here, the curves of mass density, elastic modulus, and
bulk viscosity are shown in FIGS. 8(a) to 8(c), respectively.
[0032] Referring now to FIG. 9, a flowchart is depicted for an
embodiment of a noninvasive measuring method for probing an
interface according to the disclosure. Reference may be made to
FIGS. 1, 2(a), and 3(a) to understand an exemplary system structure
applying the method of the present embodiment. The noninvasive
measuring method for probing an interface in the present embodiment
comprises the elements of: at element S110, providing a transducer
whose thickness is between 1 nm to 10 nm and is covered by a
buffering film to generate an acoustic wave whose frequency is
higher than 300 GHz; at element S120, calibrating with the
measurement of the reflection of the acoustic wave reflecting at
the surface of the buffering film which is not affected by an
object to be measured; at element S130, measuring the reflection of
the acoustic wave reflecting at the interface between the buffering
film and the object to be measured; and at element S140, comparing
the two measured reflections to analyze at least one physical
property of the interface. Reference may be made to related
paragraphs in the above described embodiments for understanding the
generation of acoustic wave, reflection of acoustic wave,
measurement of the reflection of the acoustic wave, and the
analyzed physical property.
[0033] Referring now to FIG. 10, a flowchart is depicted for
another embodiment of a noninvasive measuring method for probing an
interface according to the disclosure. Reference may be made to
FIGS. 1, 2(b), and 3(b) to understand an exemplary system structure
applying the method of the present embodiment. The noninvasive
measuring method for probing an interface in the present embodiment
comprises the elements of: at element S110, providing a transducer
which thickness is between 1 nm to 10 nm and is covered by a
buffering film to generate an acoustic wave which frequency is
higher than 300 GHz; at element S220, for a more conscientious
result of attenuation loss of the reflection of the acoustic wave
propagating back from the free surface of the object to be
measured, the calibration is carried out with the measurement of
the reflection of the acoustic wave reflecting at the interface
between the buffering film and an object to be measured first;
then, at element S230, measuring the reflection of the acoustic
wave reflecting at the surface of the object to be measured free
from the interface between the buffering film and the object; and
at element S140, comparing the two measured reflections to analyze
at least one physical property of the interface.
[0034] It is to be understood that these embodiments are not meant
as limitations of the disclosure but merely exemplary descriptions
of the disclosure with regard to certain specific embodiments.
Indeed, different adaptations may be apparent to those skilled in
the art without departing from the scope of the annexed claims.
* * * * *